Abscess: Symptoms, Causes, Treatment and Tests - What is an Abscess?

Abscess Overview

An abscess is a tender mass generally surrounded by a colored area from pink to deep red. Abscesses are often easy to feel by touching. The middle of an abscess is full of pus and debris.

Painful and warm to touch, abscesses can show up any place on your body. The most common sites are in your armpits (axillae), areas around your anus and vagina (Bartholin gland abscess), the base of your spine (pilonidal abscess), around a tooth (dental abscess), and in your groin. Inflammation around a hair follicle can also lead to the formation of an abscess, which is called a boil (furuncle).

Unlike other infections, antibiotics alone will not usually cure an abscess. In general an abscess must open and drain in order for it to improve. Sometimes draining occurs on its own, but generally it must be opened by a doctor in a procedure called incision and drainage (I&D).

Abscess Causes

Abscesses are caused by obstruction of oil (sebaceous) glands or sweat glands, inflammation of hair follicles, or minor breaks and punctures of the skin. Germs get under the skin or into these glands, which causes an inflammatory response as your body's defenses try to kill these germs.

The middle of the abscess liquefies and contains dead cells, bacteria, and other debris. This area begins to grow, creating tension under the skin and further inflammation of the surrounding tissues. Pressure and inflammation cause the pain.

People with weakened immune systems get certain abscesses more often. Those with any of the following are all at risk for having more severe abscesses. This is because the body has a decreased ability to ward off infections.

  • Chronic steroid therapy

  • Chemotherapy

  • Diabetes

  • Cancer

  • AIDS

  • Sickle cell disease

  • Leukemia

  • Peripheral vascular disorders

  • Crohn's disease

  • Ulcerative colitis

  • Severe burns

  • Severe trauma

  • Alcoholism or IV drug abuse

Other risk factors for abscess include exposure to dirty environments, exposure to persons with certain types of skin infections, poor hygiene, and poor circulation.

Abscess Symptoms

  • Most often, an abscess becomes a painful, compressible mass that is red, warm to touch, and tender.

  • As some abscesses progress, they may "point" and come to a head so you can see the material inside and then spontaneously open (rupture).

  • Most will continue to get worse without care. The infection can spread to the tissues under the skin and even into the bloodstream.

  • If the infection spreads into deeper tissue, you may develop a fever and begin to feel ill.

The symptoms of an abscess depend on where it develops in your body.

Skin abscesses

Skin abscesses often develop into a swollen, pus-filled lump under the surface of the skin, or they may appear as an open break in the skin. Abscesses are often red and painful. Boils are a common type of skin abscess.

If you have a skin abscess, you may have the following symptoms:

  • a smooth swelling under your skin that can feel hard or firm

  • tenderness in the affected area

  • pain, warmth and redness (erythema) in the affected area

  • an open wound or closed sore

  • pus in the affected area that appears white or yellow

  • a high temperature (fever) of 38C (100.4F) or above

  • chills

Skin abscesses are typically 1-3cm in diameter, although size can vary. The skin over the abscess may be thin if it is close to tearing.

Internal abscesses

Internal abscesses are more difficult to identify than skin abscesses. They can develop inside an organ, such as in the lungs or brain, or in the spaces between organs, causing pain in the affected area.

Symptoms of an internal abscess may include:

  • discomfort in the area of the abscess

  • feeling generally unwell 

  • a high temperature (fever) of 38C (100.4F) or above

  • pain in your abdomen (tummy)

The symptoms of certain types of deep abscess can also include:

  • weight loss

  • loss of appetite

  • pain and tenderness

  • drowsiness (fatigue)

  • lack of appetite

  • diarrhoea (loose, watery stools)

  • a need to frequently pass urine

Types of abscess

Depending on exactly where inside your body the abscess is, you may also have a number of other symptoms.

For example:

  • a dental abscess can cause toothache, a bitter taste in your mouth and bad breath

  • a breast abscess can cause redness, pain and a discharge from your nipple

  • a brain abscess can cause a headache, confusion and a high temperature (fever) of 38C (100.4F) or above

Abscess Treatment: Self-Care at Home

  • If the abscess is small (less than 1 cm or less than a half-inch across), applying warm compresses to the area for about 30 minutes 4 times daily can help.

  • Do not attempt to drain the abscess by pressing on it. This can push the infected material into the deeper tissues.

  • Do not stick a needle or other sharp instrument into the abscess center because you may injure an underlying blood vessel or cause the infection to spread.

When to Seek Medical Care

Call your doctor if any of the following occur with an abscess:

  • You have a sore larger than 1 cm or a half-inch across.

  • The sore continues to enlarge or becomes more painful.

  • The sore is on or near your rectal or groin area.

  • You have a fever of 38.5°C (101.5°F) or higher.

  • You have a red streak going away from the abscess.

  • You have any of the conditions listed above.

Go to a hospital’s Emergency Department if any of these conditions occur with an abscess:

  • Fever of 39°C (102°F) or higher, especially if you have a chronic disease or are on steroids, chemotherapy, or dialysis

  • A red streak leading away from the sore or with tender lymph nodes (lumps) in an area anywhere between the abscess and your chest area (for example, an abscess on your leg can cause swollen lymph nodes in your groin area)

  • Any facial abscess larger than 1 cm or a half-inch across

Exams and Tests

The doctor will take a medical history and ask for information about the following:

  • How long the abscess has been present

  • If you recall any injury to that area

  • What medicines you may be taking

  • If you have any allergies

  • If you have had a fever at home

  • The doctor will examine the abscess and surrounding areas. If it is near your anus, the doctor will perform a rectal exam. If an arm or leg is involved, the doctor will feel for a lymph gland either in your groin or under your arm.

Medical Treatment

  • The doctor may open and drain the abscess.

  • The area around the abscess will be numbed with medication.

    • It is often difficult to completely numb the area, but in general local anesthesia can make the procedure almost painless.

    • You may be given some type of sedative if the abscess is large.

  • The area will be covered with an antiseptic solution and sterile towels placed around it.

  • The doctor will cut open the abscess and totally drain it of pus and debris.

  • Once the sore has drained, the doctor will insert some packing into the remaining cavity to minimize any bleeding and keep it open for a day or two.

    • A bandage will then be placed over the packing, and you will be given instructions about home care.

    • Most people feel better immediately after the abscess is drained.

    • If you are still experiencing pain, the doctor may prescribe pain pills for home use over the next 1-2 days.

Next Steps: Follow-up

Follow carefully any instructions your doctor gives you.

  • The doctor may have you remove the packing yourself with instructions on the best way to do this. This may include soaking or flushing.

  • Be sure to keep all follow-up appointments.

  • Report any fever, redness, swelling, or increased pain to your doctor immediately.


  • Maintain good personal hygiene by washing your skin with soap and water regularly.

  • Take care to avoid nicking yourself when shaving yourself.

  • Seek immediate medical attention for any puncture wounds, especially if:

    • You think there may be some debris in the wound

    • You have one of the listed medical conditions

    • You are on steroids or chemotherapy


  • Once treated, the abscess should heal.

  • Many people do not require antibiotics.

  • The pain often improves immediately and subsides more each day.

  • Wound care instructions from your doctor may include wound repacking, soaking, washing, or bandaging for about 7 to 10 days. This usually depends on the size and severity of the abscess.

  • After the first 2 days, drainage from the abscess should be minimal to none. All sores should heal in 10-14 days.

Abscess (More Information)

An abscess is a collection of pus in any part of the body that, in most cases, causes swelling and inflammation around it.


Abscesses occur when an area of tissue becomes infected and the body's immune system tries to fight it. White blood cells move through the walls of the blood vessels into the area of the infection and collect in the damaged tissue. During this process, pus forms. Pus is the buildup of fluid, living and dead white blood cells, dead tissue, and bacteria or other foreign substances.

Abscesses can form in almost any part of the body. The skin, under the skin, and the teeth are the most common sites. Abscesses may be caused by bacteria, parasites, and foreign substances.

Abscesses in the skin are easy to see. They are red, raised, and painful. Abscesses in other areas of the body may not be seen, but they may cause organ damage.

Types of abscesses include:

  • Abdominal abscess

  • Amebic liver abscess

  • Anorectal abscess

  • Bartholin's abscess

  • Brain abscess

  • Epidural abscess

  • Peritonsillar abscess

  • Pyogenic liver abscess

  • Skin abscess

  • Spinal cord abscess

  • Subcutaneous abscess

  • Tooth abscess

Exams and Tests

Often, a sample of fluid will be taken from the abscess and tested to see what type of germ is causing the problem.


Treatment varies, but often surgery, antibiotics, or both are needed.

When to Contact a Medical Professional

Call your health care provider if you think that you may have any type of abscess.


Preventing abscesses depends on where they develop. For example, good hygiene can help prevent skin abscesses. Dental hygiene and routine care will prevent tooth abscesses.

Abscess Scan - Radioactive


Radioactive abscess scan uses white blood cells tagged with a radioactive substances and x-rays to look for abnormal sites of inflammation in the body.

Alternative Names

Radioactive abscess scan; Abscess scan

How the test is performed

Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

The blood sample is then sent to the lab where they isolate the white blood cells (WBCs), and tag them with a radioactive substance called indium. The cells are then reinjected back into a vein in your body through another needle stick.

You will have an appointment to return after 24 - 48 hours for a nuclear medicine scan to determine if WBCs have gathered outside the liver, spleen and bone marrow.

How to prepare for the test

You must wear a hospital gown and remove all jewelry.

Tell the health care provider if you are pregnant. This procedure is NOT recommended if you are pregnant.

You should also tell your health care provider if you have or had any of the following medical conditions, procedures, or treatments, as they can interfere with test results:

  • Gallium (Ga) scan within the previous month

  • Hemodialysis

  • Hyperglycemia

  • Total parenteral (through an IV) nutrition

  • Steroid therapy

  • Long-term antibiotic therapy

How the test will feel

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

The nuclear medicine scan is painless. There may be some discomfort lying flat and still on the scanning table for a short period of time.

Why the test is performed

This test is used to identify an abscess in the body when a person has signs and symptoms of sepsis, or your health care provider wants to know the cause of surgical complications.

White blood cells are the body's means of fighting infection, and this test allows your health care provider to follow these cells and see if they are gathering around a site of infection. It is expected that there will be groupings of white blood cells in the liver, spleen, and bone marrow, but if groupings of cells exist elsewhere, an abscess or other inflammatory process is possible.

Normal Values

Normal findings would show no abnormal gathering of white blood cells.

What abnormal results mean

A gathering of white blood cells outside of the normal areas is a sign of either an abscess or other type of inflammatory process.

What the risks are

  • Some bruising may occur at the site of injection.

  • There is always a slight chance of infection when the skin is broken.

  • There is low-level radiation exposure.

Radioactive injections are monitored and controlled to provide the minimum amount of radiation exposure needed to produce the image. Most experts feel that the risk is very low compared with the benefits.

Pregnant women and children are more sensitive to the risks of the x-ray.

Causes of an Abscess 

Most abscesses are caused by a bacterial infection.


When bacteria enter your body, your immune system tries to fight the infection by sending white blood cells to the affected area. As the white blood cells attack the bacteria, it causes inflammation (swelling) and the death of nearby tissue, leading to the formation of a cavity.

The cavity fills with pus to form the abscess. The pus contains a mixture of dead tissue, white blood cells and bacteria. The abscess may get larger and more painful as the infection continues and more pus is produced.

Staphylococcus aureus and streptococci are the most common types of bacteria that cause skin abscesses on the following areas of the body:

  • head and neck

  • limbs

  • underarms

  • torso

Read more information about Staphylococcal infections.

PVL Staphylococcus aureus

Staphylococcus aureus (S. aureus) is a type of bacterium found on the surface of healthy skin, particularly in the nose and moist, damp areas such as armpits and groins. It can cause skin infections, such as skin abscesses and boils, and prefers to live in moist areas of the body such as the armpits and groin. 

Some S. aureus bacteria can produce a poisonous substance called Panton-Valentine leukocidin (PVL), which kills the white cells, causing the body to make more white cells to continue to fight the infection.

PVL-positive strains of bacteria are therefore more likely to cause skin infections and abscesses.

Both types of S. aureus can also cause more serious conditions such as:

  • septicaemia – blood poisoning caused by bacteria multiplying in the blood

  • pneumonia – swelling (inflammation) of the lungs caused by an infection

Skin abscesses

Bacteria can cause a skin abscess when they get under the surface of your skin. An abscess may occur if you have a minor skin wound, such as a small cut or graze, or if a sebaceous gland (oil gland) or a sweat gland in your skin becomes blocked.

Boils develop as the result of bacteria entering the root of a hair on your skin.

In most cases, skin abscesses are not a sign of an underlying health problem. However, you are more likely to develop a skin abscess if you have diabetes. Diabetes can cause nerve damage, which can mean you are unable to feel minor cuts and grazes to your skin.

Meticillin-resistant Staphylococcus aureus (MRSA) has been a common cause of skin abscesses in recent years. Read more about MRSA infection.

Internal abscesses

Abscesses that occur in the abdomen (tummy) can be caused by:

  • an infection

  • a tear (rupture) of the intestine

  • an injury

  • surgery to the abdomen

An abscess can develop inside your body when bacteria spread from an existing infection.

For example, a lung abscess can occur as a result of a bacterial infection in your lungs, such as pneumonia (inflammation of the lung tissue), that becomes isolated by the body's immune system. This then develops into a collection of pus (abscess). Bacteria can also spread from other areas of your body through your bloodstream.

Internal abscesses tend to develop in people who have an underlying health problem, such as a brain abscess that occurs after a head wound. Internal abscesses are also more common in people with weakened immune systems, such as those with HIV and AIDS or cancer.

Risk factors

Things that increase the likelihood of an abscess developing include:

  • trauma to a specific area of the body

  • a weakened immune system

  • any material getting into the body

  • a drainage system in the body becoming blocked

  • a build-up of fluid in the tissues of the body

  • a haematoma (collection of blood outside a blood vessel)

  • a PVL-positive strain of bacteria (see above)

Hidradenitis Suppurativa

Hidradenitis suppurativa is a rare inflammatory skin disease that can cause painful abscesses to appear in the armpits and groin.

It is a chronic (long-term) disease that often begins between ages 20-40. It is also more common in females.

The condition is believed to be caused by pores of the apocrine glands (found in the armpits and groin) becoming blocked, but the exact cause is not fully known.

Severe cases of hidradenitis suppurativa can lead to psychological affects or inflammation of the joints (arthritis).

What is an Abscess and What Causes It?

An abscess is a collection of pus. Pus is a thick fluid that usually contains white blood cells, dead tissue and bacteria (germs). The usual cause of an abscess is an infection with bacteria. Certain bacteria are more likely to be 'pus forming' as they make toxins (chemicals) that can damage the body's tissues. These include: Staphylococcus aureus and Streptococcus pyogenes. The infection causes the immune system to activate white blood cells and chemicals to fight the bacteria. In this 'battle' some tissue dies. A cavity forms and fills with pus. The cavity becomes bigger if the infection continues.

Where do Abscesses Form?

  • The skin. Most abscesses form just under the skin. A boil is the most common example. In this case, a hair root becomes infected and develops into a small abscess. The skin next to the anus is another common area for an abscess to develop. The symptoms of a skin abscess include: swelling, redness, pain, and warmth over the affected area.

  • Inside the body. An abscess sometimes forms inside the body within an organ or in a space between organs. Various symptoms may occur, depending on the site of the abscess. An ultrasound scan, or other types of scan, can confirm a suspected abscess.

Who gets Abscesses?

Most skin abscesses occur in people who are otherwise well. There is often no underlying cause, and no further problems usually occur once it has gone. Your doctor may check your urine for sugar, as abscesses tend to occur more often in people with diabetes. Recurring skin abscesses may be the first indication of a problem with your immune system.

An abscess inside the body usually occurs in people who are ill with other problems, or in people whose immune system is not working well. For example: a lung abscess may form following a bout of pneumonia; a brain abscess may form after a penetrating head wound, etc.

What is the Treatment for an Abscess?

Antibiotics are usually prescribed and the pus usually needs to be drained away. For a skin abscess, this involves a small operation to cut the top of the skin and allow the pus to drain. A scar will form as the skin heals. A more sophisticated operation is needed to drain an abscess from inside the body. The techniques vary, depending on the site of the abscess.

What Would Happen if an Abscess were not Treated?

A skin abscess would normally eventually burst on to the skin surface and let out the pus. This may be after it becomes larger and more painful. So, antibiotics and surgical drainage are usually best. However, a small boil may burst and heal without treatment. An untreated abscess inside the body is usually very serious. You are likely to become very ill and treatment is usually needed.

Spinal Cord Abscess

Spinal cord abscess is swelling and irritation (inflammation) and the collection of infected material (pus) in or around the spinal cord.


A spinal cord abscess is caused by an infection inside the spine. An abscess of the spinal cord itself is very rare. A spinal abscess usually occurs as an epidural abscess.

Pus forms as a collection of:

  • Destroyed tissue cells

  • Fluid

  • Live and dead bacteria and other microorganisms

  • White blood cells

The pus is commonly covered by a lining or membrane that forms around the edges. The pus collection causes pressure on the spinal cord.

The infection is usually due to bacteria. Often it is caused by a staphylococcus infection that spreads through the spine. It may be caused by tuberculosis in some areas of the world, but it is not as common today as it was in the past. In rare cases, the infection may be due to a fungus.

The following increase your risk of a spinal cord abscess:

  • Back injuries or trauma, including minor ones

  • Boils on the skin, especially on the back or scalp

  • Complication of lumbar puncture or back surgery

  • Spread of any infection through the bloodstream from another part of the body (bacteremia)

The infection often begins in the bone (osteomyelitis). The bone infection may cause an epidural abscess to form. This abscess gets larger and presses on the spinal cord. The infection can spread to the cord itself.

The disorder is rare, but may be life-threatening.


  • Chills

  • Fever

  • Loss of bladder or bowel control

  • Loss of movement of an area of the body below the abscess

  • Loss of sensation of an area of the body below the abscess

  • Low backache, often mild but slowly gets worse

    • Pain typically moves to the hip, leg, or feet

    • Pain may spread to the shoulder, arm, or hand

  • Severe back pain

Exams and Tests

A physical exam often shows tenderness over the spine. An exam may show signs of:

  • Spinal cord compression

  • Paralysis of the lower body (paraplegia) or of the entire trunk, arms, and legs (quadriplegia)

  • Changes in sensation below the area of involvement

The amount of nerve loss depends on where the lesion is located on the spine and how much it is compressing the spinal cord.

Tests that may be done:

  • CT scan of the spine

  • Draining of abscess

  • Gram stain and culture of abscess materia

  • MRI of the spine


The goals of treatment are to relieve pressure on the spinal cord and cure the infection.

Urgent surgery to relieve the pressure is sometimes recommended. It involves removing part of the spine bone and draining the abscess. Sometimes it is not possible to completely drain the abscess.

Antibiotics are used to treat the infection. They are usually given through a vein (IV).   

Outlook (Prognosis)

How well a person does after treatment varies. Some people recover completely.

An untreated spinal cord abscess can lead to spinal cord compression. It can cause permanent, severe paralysis and nerve loss. It may be life-threatening.

If the abscess is not drained completely, it may return or cause scarring in the spinal cord.

Possible Complications

The abscess can either injure the spinal cord from direct pressure, or it can cut off the blood supply to the spinal cord.

Complications may include:

  • Infection returns

  • Long-term (chronic) back pain

  • Loss of bladder/bowel control

  • Loss of sensation

  • Male impotence

  • Weakness, paralysis

When to Contact a Medical Professional

Go to the emergency room or call the local emergency number (such as 911) if you have symptoms of spinal cord abscess.


Thorough treatment of boils, tuberculosis, and other infections decreases the risk. Early diagnosis and treatment are essential to prevent complications.

Free DVDs, Articles and Books